“Humpbacks create bubble clouds to corral their prey and then lunge through the center to swallow the small fish,” according to the NOAA press release. “Fishermen or boaters in these bubble patches run the risk of colliding with a massive whale as it rapidly approaches the surface.”

All whales in U.S. waters are protected under the Endangered Species Act and the Marine Mammal Protection Act, which makes it illegal for people to harm, injure, kill, chase or harass them, according to the press release. Harassment includes any activity that results in changes to the whales’ natural behaviors, such as feeding.

Penalties for Marine Mammal Protection Act violations are fines of up to $20,000 and up to one year in prison.

“In addition to keeping a sharp lookout, we also ask that — should the whales approach your boat — you put your boat in neutral until they have passed safely,” Mendy Garron, a NOAA spokesperson, said in a press release. “Also, please report any sightings. Locating the whales will help us keep them safe.”

To report a sighting, contact the NOAA Fisheries’ Marine Mammal Stranding and Entanglement Hotline at 866-755-NOAA (6622) or the Riverhead Foundation for Marine Research and Preservation’s stranding hotline at 631-369-9829.